This invention relates to a mold with integral screen and method for making the same and particularly to a mold with integral latticework particularly useful as a tool for making articles from a fiber or pulp slurry to provide molded pulp parts and an apparatus and method for using the mold to produce molded pulp parts.
Molds have heretofore been provided for producing molded fiber products. Typically such molds have been called wet molds because they are dipped into a wet vat of a fiber or pulp slurry. Such a slurry typically is made from reclaimed paper such as newspapers, corrugated material and the like. Such molds often have been formed of aluminum to provide the desired surface or face through which vacuum holes extend. In such molds, the surface of the mold is typically covered with a screen such as of stainless steel which is sized to fit and cut and spot welded to conform precisely to the surface of the mold to provide the mold surface. Such screens are used to prevent the fibers from clogging the vacuum holes. Such a screen makes it possible to disperse the vacuum evenly over the entire surface of the mold and to prevent the fibers from clogging the vacuum holes. Such molds typically are quite expensive because of the time required to make the mold. In addition with such molds, the screens can readily tear during production requiring that the screens be repaired or replaced. There is therefore a need for a new and improved mold or die which overcomes the above-identified disadvantages.
In general, it is an object of the present invention to provide a mold or die that has a body with an integral screen or latticework and method for making the same which greatly reduces the time and expense required for making a mold suitable for molding products from fiber or paper pulp.
Another object of the invention is to provide a mold or die and method of the above character in which the die can be provided which has a body that is integral with the latticework and in which the body and the latticework can be fabricated at the same time by the use of the same material.
Another object of the invention is to provide a mold or die and method of the above character which can readily accommodate complex shapes.
Another object of the invention is to provide a mold or die and method of the above character which provides a molded product having unique surface texture provided by the latticework of the mold or die.
Another object of the invention is to provide a mold or die and method of the above character in which the architecture of the mold incorporates a body of the material which does not adversely affect operation of the latticework or screen.
Another object of the invention is to provide a mold or die and method of the above character in which the mold or die can be created with great precision.
Another object of the invention is to provide a die and integral screen of the above character which can be produced rapidly with great precision and at a greatly reduced cost.
Another object of the invention is to provide an apparatus and method for using the mold or die of the above character in which the molded pulp product can be dried by the use of heat on the mold before the product is transferred.
Another object of the invention is to provide an apparatus and method using the mold or die of the above character in which a vacuum can be maintained on the molded product while heat is being applied to the molded product.
Another object of the invention is to provide an apparatus and method of the above character in which the mold or die when in use will permit liquid to pass through the mold or while retaining the fibers of the molded pulp on the surface of the mold or die.
Another object of the invention is to provide an apparatus and method of the above character which is used for producing a precision molded product.